Chichimene field T2 sand: a successful application of cycles in a water injection project on heavy crude oil, enabled by a novel smart selective completion system adapted for water injection

Abstract

This paper presents the application of injection in cycles, assisted by the first smart selective completion system with remote valve operation. The completion system was installed in the Chichimene Field unit T2 (Fm. San Fernando). The results were compared with conventional water injection, technology that utilizes a simple selective completion system, in the aspects of recovery factor, water consumption, operation style, and others.

The target unit has been subjected to selective water injection since 2016, this process consisted of injection of a controlled amount of water within 3-4 zones in equilibrium with the extractive system on producers wells to find a better crude oil movement and a commercial recovery factor. Despite this, the surveillance evidence suggests that some zones consume too much water due its high permeability (heterogeneity) and this impacts on high water cut on producers due to the (adverse mobility ratio), but also suggested that there is a better way to improve even more the recovery factor. This enhancement was enabled with a smart selective completion system by promoting a scheduled temporal closure of zones while production continues, achieving pressure-production restoration effects on the closed zones, allowing an efficiency increase of the vertical and areal sweep.

To determine if this could work, a smart completion system was installed in one well in August 2019.  During more than one year, the operation and interpretation of the DAS measuring tool (Continuous sound recording) was understood, from which injected water per zone is daily known, with this, the optimization of the injection rate per zone allowed enhancement of the production pattern behaviour. In February 2021, the injection cycles started on the well by zone, and to the current date, more than 25 monthly cycles have been done, increasing the recovery factor, with a considerable reduction in water and energy consumption, maintaining a continuous measurement of zone injection, this level of information has never been reached in the industry.

The case study establishes a new frontier in the field of selective injection and in cycles as well, allowing an evolution step in water injection technology. This pilot combined in one design:  selective injection, intelligent remote operate completions, continuous layer injection measuring by DAS, extra heavy oil WF, management of high permeability variations and it is aligned with the latest regulations in decarbonization (water and energy saving). From a reservoir point of view, it has never been there, a surveillance in injectors with this level of quality to enhance performance, and on the surface, this technology has allowed an important reduction in the use of wirelines for well operations and improve some well cleaning interventions with coiled tubing.